A broad region across the northeast from D.C. to Maine are now experiencing wind gusts of 50 to 80 mph or more with local power outages and downed lines reported over a broad region. The gusts are so strong and widespread that diverse locations all throughout the Northeast are seeing instances of toppled trees, damage to structures and falling limbs. In Chambersburg, PA, the raging gusts tipped over a school bus.

(A broadening storm is lashing most of the Northeastern U.S. with gale and hurricane force winds even as a places like Boston face massive waves and record storm surge flooding. Image source: Earth Nullschool.)

But what is, perhaps, more concerning is the fact that this storm is still gathering strength. And due to a blocking high over Greenland, the storm — dubbed Riley — is likely to only slowly move off-shore. So its impacts will tend to persist for multiple high tide cycles even as its circulation broadens and it generates an east-to-west fetch of gale to hurricane force winds stretching over a 400 to 600 mile region of ocean and driving directly toward the Northeast and East Coasts.

This will enable a long-lasting storm surge that will generate serious flooding for hundreds of miles of coastline. And on top of that surge, towering waves will relentlessly batter the coast throughout Friday and Saturday. Already the flooding has become quite severe for a number of locations. But the situation is likely to get worse before it gets better. With the worst impacts expected at high tide late tonight.

Scenes like these bring back recollections of Sandy. And like Sandy, the present cyclone has been influenced in a number of ways by human-caused climate change.

The storm’s historic intensity was first fed by a large plume of moisture issuing off a much warmer than normal Gulf of Mexico. Instability, driven by a deep diving trough, formed a low sweeping over the north-central U.S. that then tapped this high volume of moisture. The latent heat in the moisture enabled stronger than normal convection which helped to spike the storm’s early intensity.

(Extremely warm sea surface temperatures both in the Gulf of Mexico and off the U.S. East Coast are helping to fuel the present storm’s record intensity. This is just one of the climate change associated factors contributing to the present storm. Image source: Earth Nullschool.)

Off shore, the Gulf Stream waters are also far warmer than normal. Ranging as high as 9 degrees Celsius above average, this abnormal heat helped to fuel a second plume of moisture and instability. And as these two areas of storminess merged, they rapidly bombed out to high intensity even as their area of storm wind circulation broadened.

To the north, a recent (climate change driven) polar warming event has generated a kind of train wreck in the upper level winds that typically hurry storm systems along. As a result of this train wreck, a blocking high over Greenland is preventing this heat-amplified storm from tracking eastward. Over the next 48 hours, this block will allow a massive pile of water and towering waves to relentlessly hammer the Northeastern and Eastern Coasts of the U.S.

(Large waves and long fetch which is predicted to be generated by this storm on Saturday could produce serious and wide-ranging impacts all up and down the Eastern Seaboard from Hatteras to Portland and points northward. Image source: Earth Nullschool.)

Presently, this storm is expected to produce the second 1 in 100 year flood event that the Boston area has seen in the past year. Under typical climate variability, the likelihood of seeing back-to-back events of this kind would be 1 in 10,000. However, due to the influences of human-caused climate change, the potential for extreme weather events like the one we are presently enduring are greatly enhanced.

Yesterday a record heatwave affecting 40 million people cracked pavement, grounded flights, threatened power grids and risked serious injuries across the Southwestern U.S. Meanwhile, today, a heavily moisture laden tropical storm Cindy is threatening to dump 10 to 15 inches or more of rain on parts of the U.S. Southeast. A pair of opposite weather extremes of the kind we’ve come to expect more and more of in a world that’s warmed by about 1.2 C above 1880s averages.

(Very extreme weather conditions settled over the U.S. on June 20. Today, Cindy is expected to bring extraordinary rainfall totals to the U.S. Gulf Coast. Video source: ClimateState.)

Record-Shattering Western Heat

Yesterday, the mercury struck a scorching 127 degrees F in Death Valley California — the hottest June 20th ever recorded for that heat-blasted lowland. Meanwhile, Death Valley-like heat spilled out over a large swath of the southwest. Phoenix fell just shy of its daily record as temperatures struck 119 F. And Las Vegas tied its all-time record of 117 F (which was set just four years ago on June 30th). Needles, Daggett and Barstow in California joined Kingman in Arizona and Desert Rock in Nevada to also break previous heat records as temperatures soared to between 111 and 115 F across these cities and towns.

(Record heat hammered the U.S. West on Tuesday spiking fire hazards, grounding planes, causing power outages and increasing the risk of heat injury. Image source: National Weather Service.)

All these severe high temperatures took a serious toll as both cities and citizens fell under blast-furnace-like conditions. In Phoenix, 43 flights were grounded. Aircraft could not generate enough lift for a safe take-off in the thin, low-density hot air. Total number flights grounded since Monday now tops 50 for the city — with more expected Wednesday when temperatures are expected to hit 118 F.

(Recent warming of ocean surfaces to well above average ranges off the U.S. West Coast have likely boosted the development of the recent western heatwave. Ocean surface warming is a signature condition of human-caused climate change. Image source: Earth Nullschool.)

A strong high pressure system and a large associated ridge aided by abnormally warm waters off the U.S. West Coast are the primary regional causes of the most recent heatwave. The pool of warm water in the Northeast Pacific — somewhat reminiscent of the Hot Blob that formed in the nearby ocean zones during 2014 and 2015 — appears to be boosting the development of upper level ridges and related surface heat over the region as temperatures climb to 10 to 25 F or more above normal for many locations. Despite recent record winter and spring rainfall for parts of the region, this new heatwave is starting to again advance drought conditions across the Southwest. Yet another hard shift in weather extremes from wet and cool to dry and hot that can likely be linked to climate change.

Cindy Ushers in Severe Flooding across the Gulf Coast

While the west scorches under extreme heat, the weather threat to the U.S. Southeast comes in the form of severe flooding. In the Gulf of Mexico, a sprawling Tropical Storm Cindy is interacting with a stalled frontal system to spike moisture levels in the atmosphere above the U.S. Gulf Coast. Already, between 3 and 9 inches of rain have fallen over parts of Louisiana, Mississippi, Florida and Alabama. But the slow-moving, heavy rain bearing Cindy is poised to dump still more.

(24 hour rainfall totals show that heavy precipitation in the range of 3 to 9 inches have already fallen across the Gulf Coast. Cindy is expected to bring even more over the coming days. Image source: NOAA.)

Imagine, for a moment, that the Earth’s atmosphere is simply a big storm-generating engine. Imagine that the ignition trigger for this engine comes in the form of heat rising off the land and ocean surface. And imagine that the engine’s fuel is water vapor evaporated by that heat.

Keep the level of heat and water vapor constant, and you’ll get a continuous, steady stream of storms firing off. But increase the heat and water vapor content, as we have over the past 137 or so years, and the storms that engine produces become a whole hell of a lot more powerful.

In this context, in the last few days record atmospheric and ocean-surface heat helped to produce some of the highest water vapor levels ever recorded over Louisiana. This extreme moisture content, in turn, sparked some of the worst flooding ever seen for the state. From the Pacific Standard:

By burning fossil fuels in such high volumes for so long, that’s what we’ve done. We’ve added heat and moisture fuel to the atmospheric engine such that historic, unprecedented rain events now seem to be a weekly occurrence. And the strength of storms hasn’t increased by only a bit: the strongest storms are now exceptionally more powerful than they were back before so much CO2 and other greenhouse gasses turned the Earth’s atmosphere into something the structures of human civilization aren’t really engineered to handle.

Today, the Earth’s atmosphere also has a bit more kick due to another contributing factor: The Earth is now cooling down from a strong El Nino that helped push the world to record-hot temperatures in 2015 and 2016. To be clear, this El Nino is not the cause of the record-hot global temperatures (nor of all the added extreme rainfall potential) — it’s the warm side of the natural variability cycle. However, when you add in human greenhouse gasses, each El Nino brings with it the risk of hitting new hottest temperatures ever. As those new hot temperatures are reached, the atmosphere gets another kick into a higher, more damaging storm-firing gear.

As El Nino cools toward La Nina, that heavy volume of extra moisture loses a bit of its atmospheric support. Imagine tons and tons of moisture held up only by the heat rising from below. Take some of that heat away, and a big portion of that huge volume of moisture is going to fall out somewhere as a big rain bomb. Over the past few days, these huge dumps of rain set their sights on Louisiana.

Over the course of the next few days, this big swirl of moisture, which in many ways resembled a tropical cyclone without the strong center of circulation, drifted west. By late Thursday, it began to move inland over sections of coastal Louisiana. It was then that the real inundation started. By Friday, reports were coming in that one foot of rain had already fallen in southeastern portions of the state. Throughout Saturday and Sunday, the rains just kept coming.

(Areas in blue on the precipitation map show regions that have received greater than one foot of rainfall over the past 72 hours. Note the huge swath in central southern Louisiana. Heavy storms have also hammered the central Mississippi River states and southeastern Texas. Image source: iWeatherNet.com.)

By early Monday, 72-hour rainfall totals showed that fully one-third of Louisiana had received more than one foot of rainfall (see map above). Local spikes within this huge swath have now exceeded twofeet with total amounts as high as 30 inches reported.

Currently, most of the eastern half of Baton Rouge and numerous adjacent communities are experiencing very severe flooding. There, 125 vehicles are reported stranded on Interstate 7 even as more than 1,000 homes have flooded. In Livingston, St. Helena Parish, and Tangipahoa Parish another 1,700 homes are reported to have flooded. With floods affecting operations, hospitals such as Ochsner Medical Center in Baton Rouge are being forced to transfer patients. Rail lines have been flooded out, telephone service cut off, and seven people are reported to have lost their lives with more missing.

(Residents must use motor boats to access homes in southeastern Louisiana as around 20,000 residents have been forced to evacuate. Image source: KVEW.)

Much of the moisture from the system that generated unprecedented flooding in Louisiana has since been pulled into a big trough stretching from Texas diagonally across the Mississippi into northeastern Ohio. Big storms are predicted to erupt along this frontal boundary today and tomorrow, with significant heavy rainfall expected.

This precipitation pattern is predicted to remain mostly in place over the coming week as the frontal boundary stalls and then sags toward Tennessee. Areas expected to see heaviest precipitation totals range from Texas through northern Louisiana and into the Great Lakes region.

It’s worth noting that there’s still a huge amount of moisture in this system. So far, NOAA-predicted precipitation amounts have come up short of the heaviest amounts hitting local regions by as much as 50 percent or more, so unfortunately we’re likely to see more flash-flooding events over a broad area as the week progresses. With so much heavy precipitation falling along the Mississippi, it’s likely that a number of significant flood pulses will be headed toward portions of that large waterway.

“I can hear your whisper and distant mutter. I can smell your damp on the breeze and in the sky I see the halo of your violence. Storm I know you are coming.”

*****

The atmospheric ingredients right now are ripe for some serious trouble. Globally, the world is just starting to back away from the hottest temperatures ever recorded. This never-before-seen heat plume, driven on by a fossil-fuel abetted warming not seen in at least 115,000 years and an extreme El Nino combined, has loaded an unprecedented amount of moisture into the Earth’s atmosphere. As El Nino shifts toward La Nina and the Earth marginally cools, a portion of this massive excess of water vapor is bound to fall out as rain — manifesting as terrible extreme precipitation episodes that can result in serious trouble. A seemingly endless procession of freak events that challenge the record books time and time again.

(Severe flooding around the world this week includes the Houston area — sections of which have essentially been crippled by 12-18 inches of rainfall over the past 24 hours. In total, more than 1,200 water rescues have been reported throughout the region. Many residents, like the gentleman above, appear to have been shocked and surprised by the flooding’s severity. Video source: Houston ABC News.)

… the Houston area was socked on Monday morning by a huge mesoscale convective system (MCS) that drifted southeast across the area, dumping eye-popping amounts of rain: 6” – 8” over central Houston, with 12” – 18” common over the far western suburbs… While individual thunderstorms often weaken after dark, the large mass of thunderstorms that makes up an MCS will often persist overnight and into the next morning, as the MCS cloud tops radiate heat to space and instability is enhanced.

The record single day rainfall total for Houston before today was 11.25 inches. It appears likely that 11.75 inches recorded at Houston International Airport today will mark a new daily high mark for a city that grew up out of fossil fuel burning but now appears to be drowning in the heat-intensified effluent. More to the point, most of Houston’s western suburbs experienced what amounts to an entire typical season’s worth of rainfall in just one 24 hour period.

(River of moisture flows up from the Equator and Gulf of Mexico and into the Houston region on Monday — spurring extreme rains that cripple the city. A pair of doggedly persistent weather systems — a blocking high to the east and an upper level low to the north contributed to the extreme weather over Houston. Climate change related features like record atmospheric moisture loading, and persistent ridge and trough generation due to Jet Stream changes likely linked to record low Arctic sea ice levels also likely influenced today’s severe storms. Image source: LANCE MODIS.)

Consistent trough generation in the Jet Stream over the area (likely influenced by record low Arctic sea ice coverage), consistent above average sea surface temperatures in the Gulf of Mexico, a strong moisture flow from a record El Nino, and record global temperatures contributing to high atmospheric moisture loadings all influenced severe storm formation over this area during recent months. Sadly, it’s a spate of severe weather that is likely to continue at least until the end of Spring.

Yesterday, tropical storm Trami churned through an abnormally hot Pacific Ocean toward an inevitable date with downpour over Taiwan and Southeastern China. There, a procession of tropical storms and monsoonal moisture had set off record floods which, by Tuesday, had resulted in the deaths of over 200 people. The now saturated region expects the arrival of Trami today, but not after the tropical monster, loaded with megatons of moisture, clashed with an already amped monsoonal flow to drench the Philippines as it emerged from a broiling Pacific Ocean.

Throughout the past month, an ocean heat dome had caused surface water temperatures to soar above 86 degrees Fahrenheit (30 degrees Celsius) over a vast swath of the Pacific Ocean just to the east of China and to the south of Japan and Korea. This powerful pool of latent Pacific heat was a major factor in the delivery of record heatwaves to China, Korea and Japan which resulted in thousands of hospitalizations and at least 100 lives lost. But yesterday, the heat and moisture rising off the Pacific would play its highly energetic part in an entirely different anomalous weather event — the inundation of the Philippine capital city of Manila.

Trami Collides with Monsoonal Flow to Produce Record Rainfall over Philippines

As Trami made her way over these hot and moisture rich waters, she grew in size until her cloud area covered a width of more than one thousand miles. Ocean temperatures soaring between 2 and 4 degrees (Fahrenheit) above average helped to pump its immense bulk full of moisture even as it became wrapped in a dense flow of monsoonal moisture proceeding from west to east off the continent.

By Monday, Trami was moving in from the east, lashing the Philippines with her dense, thunderstorm laden, spiral bands even as monsoonal storms came into collision with these bands from the west. The combination of a moisture rich tropical storm colliding with an equally rain dense monsoonal flow over a Philippines surrounded by anomalously hot water set off an extraordinarily intense rain event in which the capital of Manila was inundated by a powerful deluge.

Rainfall rates for this sprawling city hit a stunning 2 inches per hour and maintained that record shattering pace for almost twelve hours running. In total, more than 23.5 inches of rainfall was recorded at rain gauges across the capital. Many residents, whose homes were flooded in a rising rush of water, were forced to evacuate and initial reports indicate that at least 100,000 of Manila’s 12 million residents have now relocated to emergency shelters. So far, at least 8 deaths and millions of dollars in damages have been attributed to the storm. But with local levees and damns under threat of over-topping and collapse, the initial reports and estimates may just be the beginning.

Satellite and water vapor imagery taken on Tuesday showed rains continuing over the Philippines, albeit at a less intense rate, as Trami turned her great bulk of moisture northwestward toward the already soaked regions of Taiwan and southeastern China. Trami is expected to intensify into a category 1 Typhoon this afternoon and is likely to deliver severe rains and flooding to already soaked regions.

You can see Trami raking both Taiwan and the Philippines with massive and rain-dense cloud bands in the most recent NOAA water vapor imagery. In this image, the storm appears to intensify as it bears down on the already storm-soaked shores of China and Taiwan.

Conditions in Context

The Philippines is hit by a total of 20 tropical cyclones each year. So heavy rainfall and floods are a regular aspect of life there. However, the nearly 24 inches of rainfall during a 12 hour period experienced yesterday is unprecedented, breaking even a number of Manila’s very high record rainfall totals. The conditions that led to these records, just one year after another severe rainfall event, include anomalous heating of the Pacific Ocean under a powerful Ocean Heat Dome during late July and early August, a rather strong and thick monsoonal flow that has tended to meander a bit further north than is usual, and a very large tropical cyclone fed by both the anomalous heat and added moisture.

Climate research has shown that we can expect more intense rainfall events worldwide as the hydrological cycle increases by 6% with a .8 degree Celsius temperature rise. Similar research has found evidence of more frequent tropical cyclones as oceans warm and seasons in which hurricanes may develop continue to lengthen. This region of the Pacific Ocean, in particular, has shown an increasing number of cyclones as Earth has continued its human-driven warming trend, with temperatures increasing by .2 degrees Celsius per decade over the last 30 years. Since the vast Pacific Ocean forms a kind of moisture trap in this steamy region, it is likely the area will experience some of the worst flooding and storm effects coming down the pipe due to human-caused warming.

Trami’s expected delivery of powerful storms to China and Taiwan will also, unfortunately, probably not be the last for this season. Water temperatures are still stunningly high and moisture flows from both the Indian Ocean and the Pacific are likely to churn out many more storms before the tropical cyclone season ends months from now.

Yesterday, a hurricane that had combined with a nor’easter and then tapped into both the powerful energies of an over-heated Atlantic Ocean and cold Arctic air seeping out through regions once encased in sea ice vented its fury on the New Jersey coastline. All up and down the Jersey Shore, community after community faced a historic storm surge born of a storm made far worse by climate change. A storm whose effects were the worst seen in this region of the US East Coast in 300 years.

Atlantic City seemed to bear the brunt of Sandy’s wrath. As early as Monday morning, the city’s coastal defenses were breached, its sea wall overwhelmed, its boardwalk washed away and its streets and homes subject to the pounding force and rush of storm waves. Residents of the barrier island community found themselves stranded as the rising tide cut off access to their community. Many fled to community storm shelters only to find the rising tide flooding these structures as well. Homes were ripped off their foundations and floated down the street or were swept into the raging Atlantic. At one point, a National Guard unit made a valiant effort to save some of those stranded by the storm. The effort was partly successful, but resulted in the loss and flooding of a number of pieces of military equipment. Overnight, the storm worsened, preventing any access to the storm-ravaged town and forcing its terrified residents to spend a water logged and fearful night alone and without public aid.

Just to the south of Atlantic City, Ocean City also faced Sandy’s terrible wrath. A seven foot water rise inundated the town and flooded its streets. As the water rose, 231 residents made emergency calls for help after refusing to heed evacuation orders. Though 50 persons were moved to escape the raging seas, miraculously no lives were lost. Almost as an after-thought Sandy parted with a 100 foot section of the Ocean City Pier.

Further north along the coast, Point Pleasant waged a valiant battle against rising seas all throughout the day. High waves and pressing tides battered the city’s beleaguered dune line. Finally, as the storm rushed in with the astronomical high tide, the dunes gave way and torrents of water rushed into the town’s streets. The city’s boardwalk was torn to shreds as boats were ripped from their moorings to float into the city where they were finally laid to rest on streets, lawns, or railroad tracks. In some places, water rushed nearly a mile inland. One home, three quarters of a mile from the shore, flooded with more than a foot of ocean water in the first floor driven in by Sandy and the 8 PM high tide.

“I kept asking him [my husband], ‘Should we go on the roof?’ I was really scared,” said Rosemary, as their house flooded. “The force and the speed that the water was pouring down and pouring over, it was scary. It rose so fast. It just kept coming and coming.”

In another part of town, firemen bravely faced the rising waters, slogging through the chest-deep flood to reach stranded residents.

The word New Jersey governor Chris Christie used to describe the wide-spread and far-ranging devastation all up and down the Jersey coast was “unthinkable.”

“The idea … that you see homes in the middle of Route 35 southbound and northbound is just unfathomable,” Christie told reporters at a morning briefing.

At 943 mb lowest central pressure, Sandy will be the most powerful storm ever to make landfall in the Northeastern US. Described as a hurricane wrapped in a Nor’easter, the beating heart of this monster storm is now growing more powerful.

Sandy’s maximum winds have intensified to 90 mph, a rapid intensification from 75 mph just 12 hours ago. It is rapidly approaching the New Jersey shore and will likely make landfall there between 8 and 11 PM this evening. Water temperatures in the region are 5 degrees Fahrenheit higher than normal and a powerful dip in the jet stream is lending energy to this immensely powerful storm.

It is difficult to underestimate the potential coastal effects of this storm, particularly to the right of the center as it comes ashore. First, the storm is coming in at or near the time of high tide, an abnormally high tide amplified by the moon. So storm surges of 4-11 feet or more will pile up on top of an abnormally high tide of 2-4 feet above mean low water. In addition, water rises of around 4 feet or more are already being recorded along the coast. This water rise is being pushed against the coast by the wind and by the force of the approaching storm. The result is that many places may see water rises of 10 feet or more above normal. Given the intensity of this storm and the fact that it is continuing to intensify as it approaches the coast, these values may be underestimated.

Maryland, Delaware, New Jersey, New York City, Rhode Island, Connecticut, and Massachusetts may all experience the highest water rise values ever seen. Already, significant flooding has occurred along the Outer Banks and into the Hampton Roads area. Below is a picture of Chicks, a popular VA Beach restaurant being flooded out by Sandy.

After two days of battering, scenes like these have become commonplace in North Carolina and Virginia Beach. But what has happened there is just a prelude to what will likely unfold over the next few hours as Sandy comes ashore.

UPDATE

Reports are coming in that Atlantic City New Jersey is now under water (11:35 Oct 29).

UPDATE:

Some locations in New Jersey are reporting 9 feet water rises. Record rise for the region are 10 feet. The below image shows Ocean City flooding.

UPDATE:

Reports are coming in that the Point Pleasant, NJ dunes have been breached and sea water is rushing through city streets like a river (7:53 PM).

UPDATE:

Some locations in New York City are reporting storm surge flooding above 9 feet (7:53 PM).

This summer, we’ve experienced record melt and heating in Greenland. Reports and satellite pictures from NASA give us a good idea of how much heat the ice sheet is receiving and what areas are melting. But this observation from the ground shows just one of the impacts of this increased melt.